In Vivo Demonstration of Enzyme Activity in Endocrine Pancreatic Tumors: Decarboxylation of Carbon-11-DOPA to Carbon-11-Dopamine

We used PET to characterize the uptake and decarboxylation of 11C-L-DOPA in vivo in two patients with endocrine pancreatic tumors: one glucagonoma and one gastrinoma. With L-DOPA labeled with 11C in the beta position, in which the radioactive label follows the molecule through decarboxylation to dop...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:The Journal of nuclear medicine (1978) 1996-01, Vol.37 (1), p.32-37
Hauptverfasser: Bergstrom, Mats, Eriksson, Barbro, Oberg, Kjell, Sundin, Anders, Ahlstrom, Hakan, Lindner, Karl Johan, Bjurling, Peter, Langstrom, Bengt
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:We used PET to characterize the uptake and decarboxylation of 11C-L-DOPA in vivo in two patients with endocrine pancreatic tumors: one glucagonoma and one gastrinoma. With L-DOPA labeled with 11C in the beta position, in which the radioactive label follows the molecule through decarboxylation to dopamine, significant uptake was observed in the tumors. With L-DOPA labeled in the carboxyl group, in which the label is rapidly eliminated from the tissue as 11CO2 if decarboxylation takes place, an almost complete lack of uptake is noted. This study shows that, using selective position labeling, an in vivo action of enzymatic activity can be observed with PET and that significant decarboxylation occurs in the tested endocrine pancreatic tumors. Also, marked retention of radioactivity occurs after treatment with somatostatin analogs. It is hypothesized that this is a reflection of a reduction of exocytosis which is induced by this treatment.
ISSN:0161-5505
1535-5667
1535-5667